Cheapest priced copy (Edge of Eternities Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Chrome Host Seedshark 
Creature — Phyrexian Shark · 2/4 · Rare · March of the Machine · #350
Flying
Whenever you cast a noncreature spell, incubate X, where X is that spell's mana value. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
6 printings · $0.49 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Edge of Eternities Commander | 68 | Rare | $0.49 | — |
| March of the Machine | 51 | Rare | $0.49 | $0.49 |
| March of the Machine | 350 | Rare | $0.99 | $0.99 |
| Media and Collaboration Promos | 2025-20 | Rare | — | $0.99 |
| March of the Machine Promos | 51p | Rare | $0.49 | $0.99 |
| March of the Machine Promos | 51s | Rare | — | $1.49Out of stock |
One ruling from Wizards of the Coast
- 14 April 2023If the noncreature spell has {X} in its mana cost, use the value chosen for X when calculating that spell's mana value.